.TH std::println(std::ostream) 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::println(std::ostream) \- std::println(std::ostream)

.SH Synopsis
   Defined in header <ostream>
   template< class... Args >
   void println( std::ostream& os, std::format_string<Args...> fmt,   \fB(1)\fP (since C++23)
   Args&&... args );
   void println( std::ostream& os );                                  \fB(2)\fP (since C++26)

   Formats args according to the format string fmt with appended '\\n' (which means that
   each output ends with a new-line), and inserts the result into os stream.

   1) Equivalent to: std::print(os, "{}\\n", std::format(fmt, args...));
   2) Equivalent to: std::print(os, "\\n");

   The behavior is undefined if std::formatter<Ti, char> does not meet the
   BasicFormatter requirements for any Ti in Args (as required by
   std::make_format_args).

.SH Parameters

   os      - output stream to insert data into

             an object that represents the format string. The format string consists of
               * ordinary characters (except { and }), which are copied unchanged to
                 the output,
               * escape sequences {{ and }}, which are replaced with { and }
                 respectively in the output, and
               * replacement fields.

             Each replacement field has the following format:

             { arg-id (optional) }               \fB(1)\fP
             { arg-id (optional) : format-spec } \fB(2)\fP

             1) replacement field without a format specification
             2) replacement field with a format specification

                           specifies the index of the argument in args whose value is
                           to be used for formatting; if it is omitted, the arguments
                           are used in order.
             arg-id      -
                           The arg-id s in a format string must all be present or all
                           be omitted. Mixing manual and automatic indexing is an
                           error.
   fmt     -               the format specification defined by the std::formatter
             format-spec - specialization for the corresponding argument. Cannot start
                           with }.

               * For basic types and standard string types, the format specification is
                 interpreted as standard format specification.
               * For chrono types, the format specification is interpreted as chrono
                 format specification.

               * For range types, the format specification is interpreted
                 as range format specification.
               * For std::pair and std::tuple, the format specification
                 is interpreted as tuple format specification.
               * For std::thread::id and std::stacktrace_entry, see       (since C++23)
                 thread id format specification and stacktrace entry
                 format specification.
               * For std::basic_stacktrace, no format specifier is
                 allowed.

               * For std::filesystem::path, see path format               (since C++26)
                 specification.

               * For other formattable types, the format specification is determined by
                 user-defined formatter specializations.
   args... - arguments to be formatted

.SH Return value

   \fI(none)\fP

.SH Exceptions

     * std::bad_alloc on allocation failure.
     * Propagate any exception thrown by any formatter, e.g. std::format_error, without
       regard to the value of os.exceptions() and without turning on ios_base::badbit
       in the error state of os.
     * May throw ios_base::failure caused by os.setstate(ios_base::badbit) which is
       called if an insertion into os fails.

.SH Notes

   Although overload \fB(2)\fP is added in C++26, all known implementations make it available
   in C++23 mode.

   Feature-test macro  Value    Std                Feature
   __cpp_lib_print    202207L (C++23) Formatted output
   __cpp_lib_format   202207L (C++23) Exposing std::basic_format_string

.SH Example

    This section is incomplete
    Reason: no example

.SH See also

   print(std::ostream) outputs formatted representation of the arguments
   (C++23)             \fI(function template)\fP
   println             same as std::print except that each print is terminated by
   (C++23)             additional new line
                       \fI(function template)\fP
   format              stores formatted representation of the arguments in a new string
   (C++20)             \fI(function template)\fP

.SH Category:
     * Todo no example
